#!/usr/bin/env python
from __future__ import absolute_import
from __future__ import print_function

from collections import deque
from contextlib import contextmanager
import logging
import os
import re
import sys

from scss import config
from scss.calculator import Calculator
from scss.compiler import _prop_split_re
from scss.compiler import Compiler
from scss.errors import SassEvaluationError
from scss.legacy import Scss
from scss.legacy import _default_scss_vars
from scss.namespace import Namespace
from scss.rule import SassRule
from scss.rule import UnparsedBlock
from scss.scss_meta import BUILD_INFO
from scss.source import SourceFile
from scss.util import profiling

try:
    raw_input
except NameError:
    raw_input = input

log = logging.getLogger(__name__)
logging.getLogger('scss').setLevel(logging.INFO)


def main():
    logging.basicConfig(format="%(levelname)s: %(message)s")

    from optparse import OptionGroup, OptionParser, SUPPRESS_HELP

    if hasattr(config.LOAD_PATHS, 'split'):
        initial_load_paths = [p.strip() for p in config.LOAD_PATHS.split(',')]
    else:
        initial_load_paths = list(config.LOAD_PATHS)

    def append_load_path(option, opt_str, value, parser):
        dest = getattr(parser.values, option.dest)
        paths = value.replace(os.pathsep, ',').replace(';', ',').split(',')
        for path in paths:
            path = path.strip()
            if path and path not in dest:
                dest.append(path)

    parser = OptionParser(usage="Usage: %prog [options] [file]",
                          description="Converts Scss files to CSS.",
                          add_help_option=False)
    parser.add_option("-i", "--interactive", action="store_true",
                      help="Run an interactive Scss shell")
    parser.add_option("-w", "--watch", metavar="DIR",
                      help="Watch the files in DIR, and recompile when they change")
    parser.add_option("-r", "--recursive", action="store_true", default=False,
                      help="Also watch directories inside of the watch directory")
    parser.add_option("-o", "--output", metavar="PATH",
                      help="Write output to PATH (a directory if using watch, a file otherwise)")
    parser.add_option("-s", "--suffix", metavar="STRING",
                      help="If using watch, a suffix added to the output filename (i.e. filename.STRING.css)")
    parser.add_option("--time", action="store_true",
                      help="Ignored, will be removed in 2.0")
    parser.add_option("--debug-info", action="store_true",
                      help="Turns on scss's debugging information")
    parser.add_option("--no-debug-info", action="store_false",
                      dest="debug_info", default=False,
                      help="Turns off scss's debugging information")
    parser.add_option("-T", "--test", action="store_true", help=SUPPRESS_HELP)
    parser.add_option("-t", "--style", metavar="NAME",
                      dest="style", default='nested',
                      help="Output style. Can be nested (default), compact, compressed, or expanded.")
    parser.add_option("-C", "--no-compress", action="store_false", dest="style", default=True,
                      help="Don't minify outputted CSS")
    parser.add_option("-?", action="help", help=SUPPRESS_HELP)
    parser.add_option("-h", "--help", action="help",
                      help="Show this message and exit")
    parser.add_option("-v", "--version", action="store_true",
                      help="Print version and exit")

    paths_group = OptionGroup(parser, "Resource Paths")
    paths_group.add_option("-I", "--load-path", metavar="PATH", type="string",
                      action="callback", callback=append_load_path, dest="load_paths",
                      default=initial_load_paths,
                      help="Add a scss import path, may be given multiple times")
    paths_group.add_option("-S", "--static-root", metavar="PATH", dest="static_root",
                      help="Static root path (Where images and static resources are located)")
    paths_group.add_option("-A", "--assets-root", metavar="PATH", dest="assets_root",
                      help="Assets root path (Sprite images will be created here)")
    paths_group.add_option("-a", "--assets-url", metavar="URL", dest="assets_url",
                      help="URL to reach the files in your assets_root")
    paths_group.add_option("-F", "--fonts-root", metavar="PATH", dest="fonts_root",
                      help="Fonts root path (Where fonts are located)")
    paths_group.add_option("-f", "--fonts-url", metavar="PATH", dest="fonts_url",
                      help="URL to reach the fonts in your fonts_root")
    paths_group.add_option("--images-root", metavar="PATH", dest="images_root",
                      help="Images root path (Where images are located)")
    paths_group.add_option("--images-url", metavar="PATH", dest="images_url",
                      help="URL to reach the images in your images_root")
    paths_group.add_option("--cache-root", metavar="PATH", dest="cache_root",
                      help="Cache root path (Cache files will be created here)")
    parser.add_option_group(paths_group)

    parser.add_option("--sass", action="store_true",
                      dest="is_sass", default=None,
                      help="Sass mode")

    options, args = parser.parse_args()

    # General runtime configuration
    if options.static_root is not None:
        config.STATIC_ROOT = options.static_root
    if options.assets_root is not None:
        config.ASSETS_ROOT = options.assets_root

    if options.fonts_root is not None:
        config.FONTS_ROOT = options.fonts_root
    if options.fonts_url is not None:
        config.FONTS_URL = options.fonts_url

    if options.images_root is not None:
        config.IMAGES_ROOT = options.images_root
    if options.images_url is not None:
        config.IMAGES_URL = options.images_url

    if options.cache_root is not None:
        config.CACHE_ROOT = options.cache_root
    if options.assets_url is not None:
        config.ASSETS_URL = options.assets_url

    # Execution modes
    if options.test:
        run_tests()
    elif options.version:
        print_version()
    elif options.interactive:
        run_repl(options)
    elif options.watch:
        watch_sources(options)
    else:
        do_build(options, args)


def print_version():
    print(BUILD_INFO)


def run_tests():
    try:
        import pytest
    except ImportError:
        raise ImportError("You need py.test installed to run the test suite.")
    pytest.main("")  # don't let py.test re-consume our arguments


def do_build(options, args):
    if options.output is not None:
        out = open(options.output, 'wb')
    else:
        out = sys.stdout
        # Get the unencoded stream on Python 3
        out = getattr(out, 'buffer', out)

    css = Scss(scss_opts={
        'style': options.style,
        'debug_info': options.debug_info,
    },
        search_paths=options.load_paths,
    )
    if not args:
        args = ['-']
    source_files = []
    for path in args:
        if path == '-':
            source = SourceFile.from_file(sys.stdin, relpath="<stdin>", is_sass=options.is_sass)
        else:
            source = SourceFile.from_filename(path, is_sass=options.is_sass)
        source_files.append(source)

    encodings = set(source.encoding for source in source_files)
    if len(encodings) > 1:
        sys.stderr.write(
            "Can't combine these files!  "
            "They have different encodings: {0}\n"
            .format(', '.join(encodings))
        )
        sys.exit(3)

    output = css.compile(source_files=source_files)
    out.write(output.encode(source_files[0].encoding))

    for f, t in profiling.items():
        sys.stderr.write("%s took %03fs" % (f, t))


def watch_sources(options):
    import time
    try:
        from watchdog.observers import Observer
        from watchdog.events import PatternMatchingEventHandler
    except ImportError:
        sys.stderr.write("Using watch functionality requires the `watchdog` library: http://pypi.python.org/pypi/watchdog/")
        sys.exit(1)
    if options.output and not os.path.isdir(options.output):
        sys.stderr.write("watch file output directory is invalid: '%s'" % (options.output))
        sys.exit(2)

    class ScssEventHandler(PatternMatchingEventHandler):
        def __init__(self, *args, **kwargs):
            super(ScssEventHandler, self).__init__(*args, **kwargs)
            self.css = Scss(scss_opts={
                'style': options.style,
                'debug_info': options.debug_info,
            },
                search_paths=options.load_paths,
            )
            self.output = options.output
            self.suffix = options.suffix

        def is_valid(self, path):
            return os.path.isfile(path) and (path.endswith('.scss') or path.endswith('.sass')) and not os.path.basename(path).startswith('_')

        def process(self, path):
            if os.path.isdir(path):
                for f in os.listdir(path):
                    full = os.path.join(path, f)
                    if self.is_valid(full):
                        self.compile(full)
            elif self.is_valid(path):
                self.compile(path)

        def compile(self, src_path):
            fname = os.path.basename(src_path)
            if fname.endswith('.scss') or fname.endswith('.sass'):
                fname = fname[:-5]
                if self.suffix:
                    fname += '.' + self.suffix
                fname += '.css'
            else:
                # you didn't give me a file of the correct type!
                return False

            if self.output:
                dest_path = os.path.join(self.output, fname)
            else:
                dest_path = os.path.join(os.path.dirname(src_path), fname)

            print("Compiling %s => %s" % (src_path, dest_path))
            dest_file = open(dest_path, 'wb')
            dest_file.write(self.css.compile(scss_file=src_path).encode('utf-8'))

        def on_moved(self, event):
            super(ScssEventHandler, self).on_moved(event)
            self.process(event.dest_path)

        def on_created(self, event):
            super(ScssEventHandler, self).on_created(event)
            self.process(event.src_path)

        def on_modified(self, event):
            super(ScssEventHandler, self).on_modified(event)
            self.process(event.src_path)

    event_handler = ScssEventHandler(patterns=['*.scss', '*.sass'])
    observer = Observer()
    observer.schedule(event_handler, path=options.watch, recursive=options.recursive)
    observer.start()
    try:
        while True:
            time.sleep(1)
    except KeyboardInterrupt:
        observer.stop()
    observer.join()


@contextmanager
def readline_history(fn):
    try:
        import readline
    except ImportError:
        yield
        return

    try:
        readline.read_history_file(fn)
    except IOError:
        pass

    try:
        yield
    finally:
        try:
            readline.write_history_file(fn)
        except IOError:
            pass


def run_repl(is_sass=False):
    repl = SassRepl()

    with readline_history(os.path.expanduser('~/.scss-history')):
        print("Welcome to %s interactive shell" % (BUILD_INFO,))
        while True:
            try:
                in_ = raw_input('>>> ').strip()
                for output in repl(in_):
                    print(output)
            except (EOFError, KeyboardInterrupt):
                print("Bye!")
                return


class SassRepl(object):
    def __init__(self, is_sass=False):
        # TODO it would be lovely to get these out of here, somehow
        self.namespace = Namespace(variables=_default_scss_vars)

        self.compiler = Compiler(namespace=self.namespace)
        self.compilation = self.compiler.make_compilation()
        self.legacy_compiler_options = {}
        self.source_file = SourceFile.from_string('', '<shell>', is_sass=is_sass)
        self.calculator = Calculator(self.namespace)

    def __call__(self, s):
        # TODO this is kind of invasive; surely it's possible to do this
        # without calling only private methods
        from pprint import pformat

        if s in ('exit', 'quit'):
            raise KeyboardInterrupt

        for s in s.split(';'):
            s = self.source_file.prepare_source(s.strip())
            if not s:
                continue
            elif s.startswith('@'):
                scope = None
                properties = []
                children = deque()
                rule = SassRule(self.source_file, namespace=self.namespace, legacy_compiler_options=self.legacy_compiler_options, properties=properties)
                block = UnparsedBlock(rule, 1, s, None)
                code, name = (s.split(None, 1) + [''])[:2]
                if code == '@option':
                    self.compilation._at_options(self.calculator, rule, scope, block)
                    continue
                elif code == '@import':
                    self.compilation._at_import(self.calculator, rule, scope, block)
                    continue
                elif code == '@include':
                    final_cont = ''
                    self.compilation._at_include(self.calculator, rule, scope, block)
                    code = self.compilation._print_properties(properties).rstrip('\n')
                    if code:
                        final_cont += code
                    if children:
                        self.compilation.children.extendleft(children)
                        self.compilation.parse_children()
                        code = self.compilation._create_css(self.compilation.rules).rstrip('\n')
                        if code:
                            final_cont += code
                    yield final_cont
                    continue
            elif s == 'ls' or s.startswith('show(') or s.startswith('show ') or s.startswith('ls(') or s.startswith('ls '):
                m = re.match(r'(?:show|ls)(\()?\s*([^,/\\) ]*)(?:[,/\\ ]([^,/\\ )]+))*(?(1)\))', s, re.IGNORECASE)
                if m:
                    name = m.group(2)
                    code = m.group(3)
                    name = name and name.strip().rstrip('s')  # remove last 's' as in functions
                    code = code and code.strip()
                    ns = self.namespace
                    if not name:
                        yield pformat(list(sorted(['vars', 'options', 'mixins', 'functions'])))
                    elif name in ('v', 'var', 'variable'):
                        variables = dict(ns._variables)
                        if code == '*':
                            pass
                        elif code:
                            variables = dict((k, v) for k, v in variables.items() if code in k)
                        else:
                            variables = dict((k, v) for k, v in variables.items() if not k.startswith('$--'))
                        yield pformat(variables)

                    elif name in ('o', 'opt', 'option'):
                        opts = self.legacy_compiler_options
                        if code == '*':
                            pass
                        elif code:
                            opts = dict((k, v) for k, v in opts.items() if code in k)
                        else:
                            opts = dict((k, v) for k, v in opts.items())
                        yield pformat(opts)

                    elif name in ('m', 'mix', 'mixin', 'f', 'func', 'funct', 'function'):
                        if name.startswith('m'):
                            funcs = dict(ns._mixins)
                        elif name.startswith('f'):
                            funcs = dict(ns._functions)
                        if code == '*':
                            pass
                        elif code:
                            funcs = dict((k, v) for k, v in funcs.items() if code in k[0])
                        else:
                            pass
                        # TODO print source when possible
                        yield pformat(funcs)
                    continue
            elif s.startswith('$') and (':' in s or '=' in s):
                prop, value = [a.strip() for a in _prop_split_re.split(s, 1)]
                prop = self.calculator.do_glob_math(prop)
                value = self.calculator.calculate(value)
                self.namespace.set_variable(prop, value)
                continue

            # TODO respect compress?
            try:
                yield(self.calculator.calculate(s).render())
            except (SyntaxError, SassEvaluationError) as e:
                print("%s" % e, file=sys.stderr)


if __name__ == "__main__":
    main()